MCP OAuth tokens expire silently mid-session breaking agent pipelines across all major clients

Every major MCP client (Claude Code, Gemini CLI, LibreChat, Codex Desktop, Open WebUI) fails to auto-refresh OAuth tokens during active agent sessions. The access token TTL (typically 1h) runs out mid-task, all tool calls return 401 silently, and the agent either stalls or reports generic errors with no recovery path. Users must manually open /mcp, reconnect each integration, and re-run the entire workflow. The MCP community formally documented this via SEP-2207 (OIDC refresh guidance, accepted Feb 2026), the TypeScript SDK merged a fix March 30, but the Python SDK fix has had no activity since March 31 and as of June 2026 the Claude Code CLI, Codex Desktop, and LibreChat all still fail in production. No standalone daemon or middleware exists that monitors active MCP sessions, detects token TTL expiry before it happens, silently refreshes via the stored refresh token, and reconnects the session without interrupting the running agent. The workaround (mcp-remote) is a manual stdio bridge that does not auto-refresh inside active sessions. Real-world impact: automated pipelines scanning multiple external sources in parallel fail silently; long-running Claude Code sessions with Atlassian, Jira, Sentry, and Slack integrations drop tools mid-task.